1. Technical Field
The present invention relates to a switching control apparatus for a two phase switched reluctance motor and a method thereof.
2. Description of the Related Art
A switched reluctance motor (hereinafter, referred to as SRM) is a motor with which a switching control apparatus is coupled and includes a stator and a rotor having a salient pole type structure.
In particular, only a stator portion is wound with a winding and a rotor portion does not have any type of windings or permanent magnets and therefore, a structure of a motor is simplified.
Due to the characteristics of the structure, it is significantly advantageous in manufacturing and production. The switched reluctance motor has excellent characteristics such as good starting property and torque like a DC motor, little maintenance, torque per a unit volume, efficiency, rating of a converter, or the like. Therefore, the switched reluctance motor has been widely applied to various applications.
There are various types of switched reluctance motors such as a single phase, a two phase, a three phase, and the like. In particular, the two-phase SRM has been significantly interested in applications, such as a fan, a blower, a compressor, and the like, by having a simpler driving circuit than that of the three-phase SRM.
Further, the switching control apparatus for the two phase SRM has used various types for controlling current of a stator winding unidirectionally. There is the switching control apparatus using an asymmetric bridge converts for driving the existing AC motor using the used types.
The asymmetric bridge converter has two switches and diodes and has a three-stage operation mode.
Herein, operation mode 1 is a mode that turns-on two switches to apply DC power supply voltage to a winding and increase current, operation mode 2 is a mode that turns-off one of the two switches when current flows in a winding to circulate current to one diode and switch and a winding and slowly reduce current, and operation mode 3 is a mode that simultaneously turns-off two switches to rapidly reduce current.
The asymmetric bridge converter operated as described above have the most excellent diversity of control among converters for driving an SRM and independently controls current of each phase to impose current superimposing of two phases. Further, the asymmetric bridge converter is suitable for high voltage and large capacity and has relatively low rated voltage of a switch.
However, the switch control apparatus for the above-mentioned two phase SRM needs two wire leader lines for each phase and has a complicated connection of wires, which increases a difficulty in a circuit design.
In addition, manufacturing costs may be increased and a large manufacturing space may be needed, due to a plurality of independent diodes that separate from switch elements.